AC motor

motor

Category:

Science & Technology

Tags:

• gadget

[naxps]

There aren't any.

[domyaska]

thank you very much from italy..very useful!

[mtdeezy]

You talked about the construction, but I still don't understand how it functions.

[Ebdan88]

What i would like to do is have 5 of these stators, and glu them together, and then use a very thick wire to rewind them. I would think that i could get around 10-15 HP.

Out of it. And then........................

[angrygunsmith]

is six pole dequivalent to six turn?

[sunwheelss]

Another loss reduction is minimising the air gap between the pole face / iron core and the rotor. These are just stock standard examples though. There are many different variables involved whether the motor is under or over rated for efficiency through things such as drives and controls.

[sunwheelss]

There are plenty of losses in an electric motor, that's just a part of it and have always and will always be around. The iron losses (from eddy currents) are reduced by using thin iron laminations (with an oxidised layer for insulation), and the other big loss is through heat and that is reduced by any or a combation of cooling vents, internal fans, external fans or forced cooling fans (hermetic compressor motors are in coolant oil)

[drum4tacos]

yeah, im very much aware of the right and left hand rules (im a mechanical engineering student) lol. dont you get a loss of flux with a ferrite-core coil? i would think they would be air-core coils to reduce flux loss.

[sunwheelss]

Since the rotor is playing 'catch up' with the rotating field it will keep spinning. This is called slip, and is why a 4 pole motor on 50Hz will not run at 1500RPM, typically will run at 1460-1490RPM. For a single phase motor you can change the direction by swapping a start and run winding lead around (the 'common') and a 3 phase you can switch any two incoming lines around. I am a qualified motor winder and should be able to answer most questions :)

[sunwheelss]

Also note that is only for one half cycle if AC, and constant for DC (obviously). For those here to learn something, on a frequency of 50Hz, each pole will be shifting 100 times a second (sine wave in two half cycles, positive then negative). What is happening in this motor is the skewed bars have a pole induced into them and then oppose their corresponding stator windings (motor windings). The rotor in turn tries to 'synchronise' with the rotating magnetic field

[sunwheelss]

the coils (wound with magnet wire) are energised and a magnetic field is induced into the iron they wrap around. The polarity of each pole can be determined by cupping your right hand and sticking your thumb straight out (right angle to your fingers). Fingers represent direction of current (coil) and thumb points to north pole. Right hand rule is for motors, left hand rule (same format) is for generators.